Means for making machine elements



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IIFA tI'. FISHER, 0F E'VNS'IN, ILLINOIS, ASSIGNOR T0 HUBLEY- MACHINECGIL?.-

DANY, I' CHICAGO, ILLINOIS, A COBJPGRA'IIII OF ILLINOIS.

A MEANS FOR MAKING MACHINE ELITLIENTE.

@riginal application medoctober la, 191e, Serial No. 258,71@ Divided andthis application tiled February le, 192e. serial No. 358,952.

To all whomz'tmay concern.'

Be it known that I, Alive J. Fianna, a citizen of the United States,residin at Evanston, in the county ofCook and tate a of Illinois, haveinvented certain new and.

useful Improvements in Means for Making Machine Itlements, of which thefollowing is a specification, this application being dlvisional of anapplication led by me on @cic aber 1s, 191s, serial No. 258,718.

My invention relates to the manufacture of machine elements, such asgears, clutchelements and the like, and has for its object to provideadvantageous means for ready l and-economical production of suchelements.'

Gears intended to be mounted on shafts, where accuracy of fit with theshaft is important, are usually machine made, but 1t .is desirable, foreconomy to cast such gears 1f possible, and in many classes ofmechanisms cast gears willperform satisfactorily 1n lleu of machine-cutgears. One of the objects of my invention is to provide for the maklngof a' cast gear that will accurately tit, and

secure proper bearing upon its rece tlve shaft, with its shaft aperturedinitial y so thatfno tooling or drilling of the shaft hole is necessaryto condition the gear for use.

. Furthermorev in many situat1ons, a gear element may beneficially by.supplemented with clutch parts-either proJectlons or 1ndentations, thesurfaces of which should be hardf,` and an object of my invention is toprovide means for making a unitary earand-clutch element having hardenedc utch surfaces.

A further object of my invention is to accommodate a simple and e'ectivemethod of casting such gears or unitary gear-andclutch elements orkindred articles of manufacture, insuring the existence in the productof the characteristics above referred to and to provide apparatus forthe simple and elicient production of the gears.

To these ends, and others that will become apparent to those `skilled inthe art, from the following description, my invention consists in thenovel features of structure and method hereinafter more fully described,and claimed.

In the drawing Fig. l is a perspective view showing the unitarygear-and-clutch .element illustrative of one machine-element suitableutobe made by the practice of my invention; Fig. 2 is a detail of a sleeve;F ig. 3 1s a detail of a chill block and core; Fig. 4 is an elevation ofa pattern; Fig. 5 shows a mold with pattern embedded therein; Fig. 6shows the mold with the pattern removed and replaced b the chill block,carrylng a sleeve; and ig. 7 shows, sectionally, completion of thecasting operation.

'Ihe specific gear 10 shown in Fig. 1, is of a construction that I usein washing machine gearing, and is of the beveled type, provided withcrown clutch projections; but it will be understood that in the broaderaspects of my invention I do not limit myself in these matters ofdetail, as my invention may be practiced in the production of many formsof gear'elements and clutch elements and other machine parts intended tointerfit with shafts and of character suitably produced by castingoperations.

In the articular article shown the hub 11 and beve ed igear teeth 12may, for many uses, ordinari y be of the relatively soft quality ofsaid-cast metal, and in many instances they have unfinished surfaces,although for liner work more cr less surface machining may be desirableand obviously employed if necessary, with some consequent increase inexpense. It is, however, usually important that the shaft hole 13 beaccurately sized and centered, and difficulty in meeting thisrequirement is an important objection to the casting lof gears and othershaft-fitting articles with pre-formed shaft holes. Clutch elements,such as the lugs 14, may best be of harder material than sand-cast ironor steel, but in many instances must be unitary with the gear element.One may fulfill both requirements by chilling the clutch surfaces insuch a unitary gear clutch element, as diagrammatically suggested by theshading at 15, Fig. 7.

'Io meet the important requirement of shaft hole sizing, one may moldaxially in the gear or kindred element a sleeve 16 of the appropriateinternal diameter, such sleeve, as indicated in Fig. 2, being preferablya true cylinder pre-formed of relatively thin metal, drawn or rolled. Inpractice satisfactory and economical use may be made of sleeves formedup of sheet steel into a seamed tube, the seam 17 being closed bywelding 18 only at the ends of the cylinder.

The cylinder is preferably slightly shorter than the full length of theshaft hole so that, in the casting operation, the cast metal may overliethe cylinder inner ends,.at certain spots, or 4throughout thecircumference of the sleeve, as the mold configuration may provide. Thusin the particular construction illiistratively shown the sleeve may becom letely overlain by the cast metal lip 19, as siiown in Fig. 7 at itsupper end, and at its lower end it is overlain at spots 20 by lips ofthe clutch projections 14.

In the production of such an article of manufacture, wherein itisrequisite that the sleeve shall accurately define the shaft holediameter. and shall be centered very accurately with respectJ to thegear-periphery or gear-toothed portion of the element, I employ theapparatus and method of produc' tion that I will now describe. I

The pattern 21, shown in Fig. 4, is suitably shaped in its central zone22 to give the desired form to the gear teeth and hub.

It is, however, supplemented by axially tapering projections 23 'and 24'to formi guide cavities in the sand. Such a pattern, placed in the sandas shown in Fig. 5, produces a cavity that gives suitable guideextensions axially beyond the central zone. The diagrammaticillustration and common knowledge of the casting art are suitable togive adequate information as to convenient construction and parting ofthe iiask, etc., without specific description. The corepiece 25, Fig. 3,having a stem 26 neatly interlitting with and supporting the sleeve 16and preferably to project slightly above the upper end thereof, andhaving a lower chill block 27 recessed as at 28 to give shape to theclutch projections 14 of the casting, and having axial guide extensions29 and 30 identically corresponding to portions (or whole) of thepattern portions 23 and 24, is fitted in the liask as shown in Fig. 6,with the sleeve in place thereon. It will be observed that the guida-nceof the parts 29 and 30 in identically shaped ortions of the mold cavityinsures abso ute precision in the centering and alignment and axialpositioning of the sleeve with respect to the mold cavity.

When the mold cavity is metal-filled, as shown in Fig. 7, the castingobviously takes the requisite form (due shrinkage allowance in the toothdimensions being made in accordance with known skillful practice). Thechill block is effective in chilling the surfaces with which it contactsto harden the active surfaces 15 of thel clutch projections 14, asheretofore referred to. The sleeve plays an important part inthematter.metal its thinness enables it to expand rapidly, andl then to shrinksufficiently with the cooling metal to resume substantially When it isinvested with the molte-nl it insures easy removability of the artic efrom the corepiece and without scoring or otherwise injuring the stem ofthe latter.

It will be apparent that the method and apparatus described areavailable in casting of parts other than the gear-and-clutch elementdescribed and while I have herein set forth the details of onesatisfactory practice and embodiment of my invention, it will beunderstood that I do not thereby limit myself to such details in thebroader aspect of my invention but lthat many changes and adaptationsmayl be made within the spirit of my invention and within the scope ofthe appended claims.

I claim:

1. Apparatus for casting machine elements having shaft-fittingapertures, comprising a pattern-member sha ed to define peripheralportions of a suitable moldcavity and guide-surfaces extraneous to saidportions at both ends thereof; a metal corepiece affording endguideportions congruent with the guide surface portions of the patternmember and having an intervening stem smaller than and forming ashoulder with one of said guide-portions of said corepiece; and a sleeveadapted to interiit with said stem and be positioned by said enlargementof the core-piece and axially remov` able over the other end of thecore-piece without injury to the stem.

2. In apparatus for casting machine elements 'having shaft-fittinga'pertlires und hardened exterior portions, a mold having a cavityproviding a metal receptive space and guide extension space, and a corepiece having a metal stem extending through the metal receptive spaceand a metal block congruent with the guide-extension space and disposedto form a wall-part of the metalreceptive space.

3. In apparatus for casting` machine elements having shaft-fittingapertures and hardened exterior portions a mold having a cavityproviding a metal receptive space and guide extension space, a corepiece having a metal stein' extending through the metal receptive spaceand a metal block congruent with the guide-extension space and disposedto form a wall-part of the metal-receptive space, and a liner-sleevesurrounding the stem and removable therefrom.

4. In apparatus for casting machine-elements having a shaft-fittingaperture and a hardened end-portion, a, horizontallydivided mold havinga cavity providing a meta-1 ,receptive space and also having in itsremet@ vstem extending vertically through the metal receptive space and,a chill-block portion congruent with and fitted in the guide-exltensionspace to define an end-portion of the metal receptive space, and a,liner-sleeve surrounding the core-stem and endwise-removable therefrom.

5. Apparatus for casting a, shaft-fitting lined gea-r with e hardenedclutch end, comprising amold, horizontally split, providing a,gear-shaping meta-l reoe tive space and at both ends thereof guie-extension spaces tapering away from the metal receptive space, a metaloore piece having a stem to extend axially through the gearsha-pingspace with its two ends shaped to fit in the guide-extension spaces, oneof seid ends being a chill-block shaped to form the end of the castinginto etoothed clutch-part, and aJ liner-sleeve surrounding the stem andendWise-removable therefrom.

ALVA Jl. FllSHlER.

